Heavy duty roof drill bit



FIG. 1 is a side elevational view of a heavy duty roof drill bit embodying the invention, the opposite side being a mirror image;

FIG. 2 is a top plan view of the heavy duty roof drill bit of FIG. 1;

FIG. 3 is a bottom view thereof;

FIG. 4 is another side elevational view of the roof drill bit, as rotated 90° from the FIG. 1, and the opposite side being a mirror image; and

FIG. 5 is a perspective view of the roof drill bit. 

The ornamental design for a heavy duty roof drill bit, as shown and described. 